Electric storage device provided with current collecting member, and method for manufacturing current collecting member

Abstract

A current collecting member includes first portion second portions. The second portion includes a base portion the first end portion of which is connected to the second end portion of the first portion, a twisted portion the first end portion of which is connected to the second end portion of the base portion, and an insertion portion the first end portion of which is connected to the second end portion of the twisted portion and which is inserted into a winding center of the electrode assembly, so as to be electrically connected to the electrode assembly.

The invention claimed is: 
     
       1. An electric storage device, comprising:
 a case; 
 an electrode assembly housed in the case and including a positive electrode plate and a negative electrode plate which are wound together while being isolated from each other; 
 an external terminal arranged outside the case; and 
 a current collecting member arranged inside the case to electrically connect the electrode assembly with the external terminal, 
 wherein the current collecting member comprises:
 a first portion including a first end portion and a second end portion and electrically connected to the external terminal; and 
 a second portion extending out of the second end portion of the first portion and electrically connected to the electrode assembly, and 
 
 wherein the second portion comprises:
 a base portion including a first end portion and a second end portion, the first end portion of the base portion being connected to the second end portion of the first portion; 
 a twisted portion including a first end portion and a second end portion, the first end portion of the twisted portion being connected to the second end portion of the base portion; 
 an insertion portion including a first end portion and a second end portion, the first end portion of the insertion portion being connected to the second end portion of the twisted portion, the insertion portion being inserted into a winding center of the electrode assembly and electrically connected to the electrode assembly; 
 a reverse-twisted portion twisted in a direction opposite to the twisting direction of the twisted portion and including a first end portion and a second end portion, the first end portion of the reverse-twisted portion being connected to the second end portion of the insertion portion; and 
 a leading end portion including an end portion, the end portion of the leading end portion being connected to the second end portion of the reverse-twisted portion, 
 
 wherein a pair of combinations each including the twisted portion, the insertion portion, and the reverse-twisted portion is provided at intervals to one another, and 
 wherein the leading end portion couples the second end portions of the pair of reverse-twisted portion with each other. 
 
     
     
       2. An electric storage device, comprising:
 a case; 
 an electrode assembly housed in the case and including a positive electrode plate and a negative electrode plate which are wound together while being isolated from each other; 
 an external terminal arranged outside the case; and 
 a current collecting member arranged inside the case to electrically connect the electrode assembly with the external terminal, 
 wherein the current collecting member comprises:
 a first portion including a first end portion and a second end portion and electrically connected to the external terminal; and 
 a second portion extending out of the second end portion of the first portion and electrically connected to the electrode assembly, 
 
 wherein the second portion comprises:
 a base portion including a first end portion and a second end portion, the first end portion of the base portion being connected to the second end portion of the first portion; 
 a twisted portion including a first end portion and a second end portion, the first end portion of the twisted portion being connected to the second end portion of the base portion; 
 an insertion portion including a first end portion and a second end portion, the first end portion of the insertion portion being connected to the second end portion of the twisted portion, the insertion portion being inserted into a winding center of the electrode assembly and electrically connected to the electrode assembly; 
 a reverse-twisted portion twisted in a direction opposite to the twisting direction of the twisted portion and including a first end portion and a second end portion, the first end portion of the reverse-twisted portion being connected to the second end portion of the insertion portion; and 
 a leading end portion including an end portion, the end portion of the leading end portion being connected to the second end portion of the reverse-twisted portion, 
 
 wherein a pair of combinations each including the twisted portion, the insertion portion, and the reverse-twisted portion is provided at intervals in parallel to one another, and 
 wherein the leading end portion couples the second end portions of the pair of reverse-twisted portion with each other. 
 
     
     
       3. The electric storage device according to  claim 1 , wherein the pair of combinations each including the twisted portion and the insertion portion is provided at said intervals in parallel to each other. 
     
     
       4. The electric storage device according to  claim 1 , wherein the twisted portion is twisted at an angle of 90 degrees, so that the base portion and the insertion portion are orthogonal to each other. 
     
     
       5. The electric storage device according to  claim 1 , wherein the twisted portion is twisted at an angle of 90 degrees, so that the base portion and the insertion portion are orthogonal to each other, and wherein the reverse-twisted portion is twisted at angle of 90 degrees in a direction opposite to the twisting direction of the twisted portion, so that the insertion portion and the leading end portion are orthogonal to each other and the base portion and the leading end portion are flush with each other. 
     
     
       6. The electric storage device according to  claim 1 , wherein the current collecting member is arranged so that the base portion faces an end face of the electrode assembly. 
     
     
       7. The electric storage device according to  claim 1 , wherein the current collecting member is arranged so that the base portion and the leading end portion face an end face of the electrode assembly. 
     
     
       8. The electric storage device according to  claim 3 , wherein each of the pair of insertion portions comprises, on a leading end side of the insertion portion in an insertion direction thereof, an inclined surface inclined so as to approach a counterpart insertion portion. 
     
     
       9. The electric storage device according to  claim 1 , wherein the second portion extends out along a plane connecting the first end portion and the second end portion of the first portion. 
     
     
       10. The electric storage device according to  claim 9 , wherein the second portion is bent with respect to the first portion. 
     
     
       11. The electric storage device according to  claim 1 , wherein the first portion and the second portion are integrally formed by processing a metal plate,
 wherein a central portion of the second portion in a width direction thereof orthogonal to an extending direction thereof is divided, thereby forming in the second portion a pair of divided portions, and 
 wherein each of the pair of divided portions includes the twisted portion and the insertion portion. 
 
     
     
       12. The electric storage device according to  claim 3 , wherein one and the other twisted portions of the pair of twisted portions are opposite to each other in the twisting direction thereof. 
     
     
       13. The electric storage device according to  claim 2 , wherein one and the other twisted portions of the pair of twisted portions are opposite to each other in the twisting direction thereof, and
 one and the other reverse-twisted portions of the pair of reverse-twisted portions are opposite to each other in the twisting direction thereof. 
 
     
     
       14. The electric storage device according to  claim 1 , wherein the base portion and the leading end portion are arranged so as to be flush with each other. 
     
     
       15. The electric storage device according to  claim 1 , wherein the positive electrode plate has a positive-electrode lead portion formed in one end portion thereof in a width direction of the electrode assembly,
 the negative electrode plate has a negative-electrode lead portion formed in one end portion thereof in the width direction of the electrode assembly, 
 the positive-electrode lead portion protrudes outward from the other end portion of the negative electrode plate in the width direction of the electrode assembly, 
 the negative-electrode lead portion protrudes outward from the other end portion of the positive electrode plate in the width direction of the electrode assembly, and 
 the current collecting member comprising a positive-electrode current collecting member to be connected to the positive-electrode lead portion and a negative-electrode current collecting member to be connected to the negative-electrode lead portion.